The markets posted strong gains in the past session. However, volume on the New York Stock Exchange has been more than 15% below average, leading some market participants to question the conviction of this week's moves.

On the economic calendar Wednesday, there are two reports due out. Economists expect 310,000 people to have filed for first-time unemployment benefits last week, from 297,000 the week prior. Another report at 10 a.m. ET could show sales of existing, single-family homes having climbed to an annual rate of 4.68 million units in April, from 4.59 million the month prior.

Continue Reading Below

ADVERTISEMENT

The economy has been bouncing back from an unusually harsh winter.

In corporate news, Best Buy (BBY) posted mixed quarterly results. Sears Holdings (SHLD) said its fiscal first-quarter loss is widening amid falling sales, sending shares of the struggling department store sliding. Hess (HES) said it will sell its retail business to Marathon Petroleum (NYSE: MPC) for $2.6 billion. JD.com (JD) is set to make its debut on the Nasdaq Stock Market under the symbol "JD."

Elsewhere, U.S. crude oil futures fell 3 cents, or 0.03%, to $104.05 a barrel. Wholesale New York Harbor gasoline rose 0.1% to $2.997 a gallon. Gold rose $9.30, or 0.72%, to $1,298 a troy ounce.